Rosen has been dealing with a nerve issue in his right (throwing) shoulder. He has missed UCLA's past two games, losses to Washington State and Utah.
Senior Mike Fafaul has taken first-team snaps in practice this week. UCLA will face Colorado on Thursday night. Fafaul has thrown for 779 yards with eight touchdown passes and eight interceptions this season for UCLA (3-5).
ESPN's Todd McShay lists Rosen as one of the top college quarterbacks, with a big arm and great instincts as a passer.